From patchwork Sat Oct 15 21:10:25 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christopher Friedt X-Patchwork-Id: 13007689 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 4944EC433FE for ; Sat, 15 Oct 2022 21:13:15 +0000 (UTC) Received: from localhost ([::1]:39584 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ojoT3-0007CV-Tl for qemu-devel@archiver.kernel.org; Sat, 15 Oct 2022 17:13:13 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:49030) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ojoRu-0006VF-0j for qemu-devel@nongnu.org; Sat, 15 Oct 2022 17:12:02 -0400 Received: from mail-qv1-xf2c.google.com ([2607:f8b0:4864:20::f2c]:35530) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1ojoRs-0001PD-A0 for qemu-devel@nongnu.org; Sat, 15 Oct 2022 17:12:01 -0400 Received: by mail-qv1-xf2c.google.com with SMTP id i12so5381621qvs.2 for ; Sat, 15 Oct 2022 14:11:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=vjXeM1qfABR/eJ/tOhGIsP0nWEQmuoVqED/OwwEVETc=; b=XU3q3vZAqNNrABkAiqtPGQBKuvKUVA/14xyI7MfX7AREpZ2ww70WtyRad6DYOJynCW FOkm+vfct9trmeOuKZHrARVNKKZDZ5dFgo/H7J2xtF21dyRx4fe6uLu9ad6DfrjOjOmu xdmRkyhrnH3bBb8Z1x3T/zYmK0dwuul9VILvygiJW7WLwib49VF41vBOFSkPPiT6HUtr 6vafpESejHBqT3jF2uwX77K3ZZ8WMWnL/lRjmjjqLVNjwQNavz1dHuARxkF8rLxwWkNh ndrN1gvEgmFhr/fN0Q8/l71UCXBs7uAOrjd/knM0Kt94jWCznLiXhbeC/SU3cklVR/S6 P/bQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=vjXeM1qfABR/eJ/tOhGIsP0nWEQmuoVqED/OwwEVETc=; b=FS++7B/peaPK65M3MK+W3hcD/wVSCLS6l19RlFxtkD0ZX0HoOmn7tSCW3JtPE7jWR5 IA+H/LdM89Ly8QxwRiB9Q1eG9hvlZaIJBtpcTyfkrGBnN5D0QOZWucfayncwadvDfW0k NQWPx6n3d2fSRFuH/Hpj43+bl3LBJaUUNJgfHiKO+BRT/Sr4wDkJLmhqoUnwuIh+FXth TRyAPVonk1hPJwfF1MdWDcozrkiUwomtLv7xYtw3hHP4bbZ1ZyvkP1TUAg0xF0cZhhu8 iCdWz61pYcYWQITZ6YOy68lynobIZIb7C04AZlHd84e15/ZNdflKASc/h3angOntdMRq Jhxw== X-Gm-Message-State: ACrzQf1bT0Vgz99tvcoe7idOlW53L1EmNIEdD6jlGEWyM768yg2NeyRC 8MJY1+WIF8N/q3owHEznuCLDVNXDAqHtNg== X-Google-Smtp-Source: AMsMyM6N1jH4NV3zahIiPD918rA4dN8klpt1snn7CqFuSTjBg+GqVzhwyuIeC5hkAgTRwIzGxv5C+A== X-Received: by 2002:a05:6214:766:b0:4b3:e83b:6e8a with SMTP id f6-20020a056214076600b004b3e83b6e8amr3348932qvz.53.1665868317917; Sat, 15 Oct 2022 14:11:57 -0700 (PDT) Received: from localhost.localdomain ([2001:1970:50d6:9900::7aa4]) by smtp.gmail.com with ESMTPSA id de4-20020a05620a370400b006e07228ed53sm5262679qkb.18.2022.10.15.14.11.56 (version=TLS1_3 cipher=TLS_CHACHA20_POLY1305_SHA256 bits=256/256); Sat, 15 Oct 2022 14:11:56 -0700 (PDT) From: Chris Friedt To: qemu-devel@nongnu.org Cc: cfriedt@meta.com, jslaby@suse.cz Subject: [v2] hw: misc: edu: fix 2 off-by-one errors Date: Sat, 15 Oct 2022 17:10:25 -0400 Message-Id: <20221015211025.16781-1-chrisfriedt@gmail.com> X-Mailer: git-send-email 2.36.1 MIME-Version: 1.0 Received-SPF: pass client-ip=2607:f8b0:4864:20::f2c; envelope-from=chrisfriedt@gmail.com; helo=mail-qv1-xf2c.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: Christopher Friedt In the case that size1 was zero, because of the explicit 'end1 > addr' check, the range check would fail and the error message would read as shown below. The correct comparison is 'end1 >= addr' (or 'addr <= end1'). EDU: DMA range 0x40000-0x3ffff out of bounds (0x40000-0x40fff)! At the opposite end, in the case that size1 was 4096, within() would fail because of the non-inclusive check 'end1 < end2', which should have been 'end1 <= end2'. The error message would previously say EDU: DMA range 0x40000-0x40fff out of bounds (0x40000-0x40fff)! This change 1. renames local variables to be more less ambiguous 2. fixes the two off-by-one errors described above. Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1254 Signed-off-by: Christopher Friedt Reviewed-by: Alexander Bulekov --- hw/misc/edu.c | 25 ++++++++++++------------- 1 file changed, 12 insertions(+), 13 deletions(-) diff --git a/hw/misc/edu.c b/hw/misc/edu.c index e935c418d4..52afbd792a 100644 --- a/hw/misc/edu.c +++ b/hw/misc/edu.c @@ -103,25 +103,24 @@ static void edu_lower_irq(EduState *edu, uint32_t val) } } -static bool within(uint64_t addr, uint64_t start, uint64_t end) +static void edu_check_range(uint64_t xfer_start, uint64_t xfer_size, + uint64_t dma_start, uint64_t dma_size) { - return start <= addr && addr < end; -} - -static void edu_check_range(uint64_t addr, uint64_t size1, uint64_t start, - uint64_t size2) -{ - uint64_t end1 = addr + size1; - uint64_t end2 = start + size2; - - if (within(addr, start, end2) && - end1 > addr && within(end1, start, end2)) { + uint64_t xfer_end = xfer_start + xfer_size; + uint64_t dma_end = dma_start + dma_size; + + /* + * 1. ensure we aren't overflowing + * 2. ensure that xfer is within dma address range + */ + if (dma_end >= dma_start && xfer_end >= xfer_start && + xfer_start >= dma_start && xfer_end <= dma_end) { return; } hw_error("EDU: DMA range 0x%016"PRIx64"-0x%016"PRIx64 " out of bounds (0x%016"PRIx64"-0x%016"PRIx64")!", - addr, end1 - 1, start, end2 - 1); + xfer_start, xfer_end - 1, dma_start, dma_end - 1); } static dma_addr_t edu_clamp_addr(const EduState *edu, dma_addr_t addr)